LEVERAGING NEUROIMAGING AND PSYCHIATRIC GENETICS FOR ASSOCIATIONS, CAUSAL RELATIONSHIPS, MECHANISMS, AND CLINICAL INSIGHTS

Overall Abstract Neuroimaging facilitates minimally-invasive measurement of various brain tissues at the structural and functional levels. In recent years, identifying neuroimaging correlates of psychiatric conditions has become a major research focus, owing to the brain’s central role in psychiatric disorders. Accordingly, numerous studies have reported neuroimaging differences between controls and individuals diagnosed with psychiatric conditions. Identifying the molecular basis of brain structure and its link to psychiatric disorders has the potential to 1) refine broad phenotypic categories into directly-measurable outcomes, 2) inform our understanding of disorder causal mechanisms, and 3) inform future clinical care. A growing body of work is contributing to an increased understanding of the neurobiology underlying psychiatric disorders and accomplishing these three goals. This symposium will catalogue recent efforts integrating neuroimaging and psychiatric genetics to identify 1) genetic correlates, 2) causal relationships, 3) underlying shared mechanisms, and 4) clinical implications. We start with a presentation by Vilte Baltramonaityte who will discuss the largest GWAS meta-analysis of brain age to date and the associations of brain age with other aging traits and psychiatric disorders. This work was accomplished in part by a large international collaboration within the ENIGMA consortium. Next, a presentation from Shane O’Connell will describe how a novel network-based approach to Mendelian Randomization can elucidate causal relationships between neuroimaging phenotypes and psychiatric disorders. This approach allows for the modelling of conditional effects that have the potential to improve prediction of psychiatric disorders and better understand how brain changes may lead to disorder onset. Yuankai He will then present work which utilizes differing genetic approaches to prioritize putative neuroimaging biomarkers of psychiatric disorders and propose mechanistic explanations for these pairings. Such triangulation identifies robust associations with the potential to reveal more reliable mechanistic insights. Finally, Nadine Parker will present work investigating the genetic link between drug treatment of psychiatric disorders and alterations in brain structure. Genetic associations between psychotropic treatment and neuroimaging features can help with understanding medication effects as confounders of phenotypic brain alterations linked to psychiatric disorders and potentially identify markers of treatment response. Overall, this symposium aims to illustrate how integrating neuroimaging and psychiatric genetics can be used for associations, causal relationships, mechanisms, and clinical insights. The result of such work further improves our understanding of complex heterogeneous psychiatric disorders and paves a path towards more objective diagnostic criteria and targeted treatment.